1. Field of Invention
This invention relates to building heating, cooling, and energy storage systems. More specifically, this invention relates to apparatuses and processes that use pressure swing adsorption and desorption to achieve heating, cooling, and energy storage.
2. Description of Prior Invention
Adsorption is emerging as an important process for separating fluids, heating, cooling, molecule storage, and energy storage. The present invention comprises a pressure swing adsorption (so called “heatless” adsorption) cycle that in a preferred embodiment provides heating, cooling and energy storage in a single adsorption cycle. In a first embodiment, the invention uses an open loop environmental air sourced adsorbate fluid which is adsorbed from air, run through one or more steps, and then released back to the environmental air. In a second embodiment, the invention uses a closed loop adsorbate fluid which is pressure swing adsorbed releasing heat, then pressure swing desorbed absorbing heat. The released heat is applied to a heating application such as heating a building and the absorbed heat is absorbed from an application to be cooled such as a building. Also the adsorption and the desorption processes are selectively separated in time such that a saturated sorption bed provides a stored capacity to cool which is utilized by simply opening a valve; similarly a regenerated sorption bed provides a stored capacity to heat which is utilized simply by opening a valve. For about 100 years, prior art temperature swing adsorption and absorption has been utilized for cooling systems such as adsorption chillers and ammonia absorption chillers. Such systems have the advantage of being relatively simple with few moving parts and being powered by burning fuel, or solar thermal energy, or waste heat energy but have the disadvantage of requiring excessive heat input for desorption and therefore have a low COP efficiency. An example of a water based temperature swing adsorption system including a storage aspect is described in an undated paper “Sorbtion Materials for Application in Solar Heat Energy Storage” by P. Gantenbein et al of the Institute for Solartechnik in Switzerland. The present invention replaces the heat input “temperature swing adsorption” and “temperature swing absorption” driven compression and phase change effect with mechanical energy input “pressure swing adsorption” driven compression and phase change effect. Moreover the prior art cycle resembles a vapor compression cycle with an evaporator, a condenser, and with the desorption process not being directly utilized for cooling an application such as a building. By contrast, the present cycle requires no evaporator, no condenser, and the desorption in the sorption bed is applied directly to a cooling application such as cooling a building. The present cycle driven by mechanical energy input from an electric compressor pump or a renewable wind driven compression pump, with the mechanical energy applied to pressure swing adsorption, or pressure swing desorption, or to both. Very recently researches have demonstrated a pressure swing adsorption process applied to producing chilled water. This demonstration is described in Chemical Engineering Journal, #171, (2011) 541-548, Titled “Experimental investigation of a single-bed pressure swing adsorption refrigeration system towards replacement of halogenated refrigerants” by Kumar Anupam et al. It is also described in India Patent Application 1153/KOL/2011 A dated Jan. 9, 2011 and published on Sep. 9, 2011 titled “An Eco-Friendly Mechanism of Cold Production to Combat With Halogenated Refrigerants”, invented by Halder Gopinath, and Kumar Anupam. In these documents, CO2 is the adsorbate, activated carbon is the adsorbent, a COP of 3.014 using a pressure swing of 0.1 MPa to 0.5 MPa, cooled water from 26° C. to 4° C. While this illustrates a prior art application of pressure swing adsorption cycle and apparatus utilized for a cooling application, the present invention describes and claims more complex cycles, integration of mechanical energy inputs, multiple adsorption beds, application of pressure swing adsorption to both heating and to cooling applications, achieving heating and cooling applications concurrently, loading one or more beds as a stored capacity to cool, regenerating one or more beds as a stored capacity to heat, using a pressure differentials to passively cool, using a pressure differential to passively heat, maximizing the effective energy storage capacity of sorption beds by inducing an adsorbate tank, a system for leveraging pressure differentials between sorption beds to maximum advantage, integrating pressure swing adsorption heating and cooling with other forms of energy transfer, and a electronic, firmware, software control system to take advantage of these preceding apparatuses, cycles, and advantages.